fUBE versus mixes cbofs. 115 



fail to attain the finest growth of which it is capable on the given 

 soil, which it will perforce gradually render more and more suit- 

 able for itself. Now mix both species together, and thanks to the 

 improvement of the soil effected by the lattter, and to the denser 

 leaf-canopy and the maintenance of favourable influences due to 

 the mixed growth, the longevity of the first must obviously be en- 

 hanced. 



XIII. By a miaituve of species a forest is generally able to yield 

 marketable produce at an earlier age than if it consisted of pure 

 cropa.— The reason is obvious. The trees, thriving better, often 

 acquire, in gpite of the closer growth, a given size at a younger 

 stage of development. But, what is more to the point, as the stems 

 in a mixed forest are more numerous, the first series of exploitations 

 to check and control the struggle for existence become necessary 

 much earher, especially if the less valuable species are the fastest- 

 growers. Besides this, in a mixed forest, owing to the different 

 habits of the trees and their different requirements as to light, not 

 only does a given number of stems form a denser leaf-canopy than 

 in a pure forest, but a gap made in that canopy is sooner filled 

 up; so that, with no heavier stock on the ground, the first cutting 

 ean generally be made earlier there, 



XIV. Mixed forests, as a rule, yield a larger revenue than pure 

 forests, provided of course that the component species are all market 

 able. — -This follows directly from all the preceding considerations. 



XV. A mixture of species gives greater elasticity to the worh- 

 ing and treatment o/ a /ore«i.— Yielding a great variety of pro- 

 ducts, a mixed forest can be worked in almost any condition of the 

 market. Containing various species, and thus composed of indi- 

 viduals possessing various capabihties, it may be adapted at once 

 to more than one method of treatment, or, at any rate, allow of 

 the rotation, the method of treatment, and even the regime, being 

 changed without difiiculty or loss of time. On the other hand, 

 when there is only a single species in the crop, the lines on which 

 work must be carried on are necessarily every inelastic, and every 

 thing must be done with a more or less mechanical regularity, 

 little scope being left for altering the system of management from 

 time to time in order to suit the ever-changing conditions of the 

 country or the market, 



XVI. A mixed forest will, unless the soil suits only a single spe- 

 cies, invariably afford better protection against erosion, landslips, ava- 

 lanches, hot or cold or violent winds, Sfc, than a 'pure forest growing 

 under identical conditions. — We have already seen that in mixed 



